Stage noise in a church/auditorium (not a studio, but...)

zikaj · Post by **zikaj** » Fri Jul 18, 2003 1:41 pm

I was wondering if you had any input on this case scenario (hoping more than wondering).

Our church sanctuary is actually a well acoustically treated gynmasium. We built that first so it is now multipurpose. There is a large stage from where a contemporary/rock/pop band plays with a choir and singers. Acoustic drums, bass amp, guitar amp, keys, percussion, sometimes strings, and a choir. There are atleast 6 stage monitors. The stage is 22 feet deep, 45 feet wide, with 2 large areas off to the sides. There is no acoustic treatment on this carpet-covered stage. The 25 foot rear wall is painted cinder block, untreated.

The problem: the stage noise level is about 100 dB, everyone turns up louder and louder, or turns up their monitor, the singers can't hear, the choir can't hear themselves (maybe standing on a carpet covered riser is part of the cause!

)....you get the idea. This then causes half of the congregation to get blown away, and the killer house sound system can't be fully utilized (a great system with 4 large banks in the air and 2 subs up front on the ground).

I was thinking of placing broadband fiberglass absorption on the stage walls with some bass trapping.

Do you think it would be of benefit to fill the 2 foot high drum riser with something or make baffles in it to decrease its resonance/noise? (its over 130 cubic feet inside). Or just decouple it from the floor?

Should I make the area behind the choir reflective, but warmer, with some 'ethan winer' style bass traps so that they are useful with bass but help throw more of the choir sond back at their ears?

As you can tell, I can go on forever! The pastor dumped this on me because i have done some friends studios here in Ohio, but this is outta my leage. But then again, I'm workin for free!

Thank you greatly!

Jeff Z

audio hobbit · Post by **audio hobbit** » Fri Jul 18, 2003 2:15 pm

wow, I sympthize with ya.. I ahev done too many church gigs over the years, as a tech that is.. first things first.. ge tth evolume down... I would seriously look into a "musio" controlled monitoring system ( look at http://www.aviominc.com/ ) that drives headphones for the band. They will hear better, you will hear better.. life will be better!

As far as acoustics.. I will leave that up to the guys here who know what they are talking about!

Feel free to e-mail me or post here if you have any questions about the "gear" side of any potential solutions.

giles117 · Post by **giles117** » Fri Jul 18, 2003 11:35 pm

And if they are resistive to the headphones....

Train your band. It is work, but I have done it at all the churchs I have engineered at over the years. I have been able to get onstage Db levels to around 92db with good training of the band.

Tune the wedges for one so that the sound from the monitors is smooth to their ears.

Then work on Monitor placement for the Band.

Do you have a dedicated Monitor Console?? That is one Major problem in a lot of churchs. 4 mixes shared with 6 band members, vocalist and the Pastor. Not good.

FInally, show up on rehearsal night, clear the politics hurdle. All churches have that hurdle and get the music department on your side. Be friendly with the guys, comment on what they played after service and what you could not hear, etc..

Be Savvy and a diplomat,3-6 months the mix will be awesome....

Like I said I have worked it everywhere I go, 'cept when dealing with immature people (15 year old drummers who think they da stuff.)

Bryan

knightfly · Post by **knightfly** » Sat Jul 19, 2003 1:33 am

Jeff, I saw your posts over at RO and wasn't sure I could help, but here's my $.02 -

First, I saw Earth, Wind and Fire in Portland Oregon a few months ago and almost couldn't STAND the sound (I love the band, so that's not it) but they had the drums on a riser on a riser (no echo in here, they were stacked on a DOUBLE riser, for a total of about 7 feet! Boy, did it look cool with those two dancers on the first riser and the drums up 'way high - and boy, did it sound CRAPPY... Oh, yeah, the whole venue is a (not so) converted theater, with a wooden stage. There was so much resonance going on, I would love to have been able to disconnect the kick drum pedal so we could stand the music.

I think the only way you're going to get that place sounding very good is to add extra joists under the floor to stiffen it, then another layer of 1-1/4" flooring plywood. Right now, you've got a massive panel trap resonating at who knows what frequency, plus more panels in the form of risers - add to that the carpet, and your choir just lost any sibilance that would let them hear individual syllables.

The next thing would be to get some of those Auralex Mo Pad isolators for the amps (the amp ones aren't called that but it's the same idea) and, as Kurt from RO said, get each player to keep his/her amp close and pointed at them more than others, so each player can hear themselves more with less volume. Remember, 6 dB per doubling of distance (free air only, but still applicable in a way) Several years ago I bought 6 small stand mounted monitors similar to (but better than) Hot Spots, and our stage levels dropped drastically because we each had vocal monitors in our face instead of 6 feet away on stage - also, these were dual 4" and tweets instead of a 15" and horn, so we weren't amping things we didn't need just to hear vocals.

I also agree that church bands bring out the least Christian aspects of some people, and that they need to learn to live with the least volume that will let them hear themselves instead of each one thinking they need to be the star of the show...

I'm not sure whether angled plywood with 705 attached would help - I think it probably would, especially at the rear where that cement block lives. Right now, everybody is getting all the direct sound plus repeats from that back wall, which is probably comb filtering EVERYTHING differently - if you could both absorb and re-direct the reflections, it would probably clear up the sound on stage so everyone didn't try to turn up when they couldn't hear.

Man, I gotta stop workin' so cheap, even if I don't know what I'm doin... Steve

giles117 · Post by **giles117** » Sat Jul 19, 2003 3:54 am

Was My Buddy Tim Colvar Mixing that EWF Show. I Love his mixes. Not sure who is the monitor guy now however....

And As I read further, yeah that wooden stage is a death trap, Bass gets all bouncy underthat thing and the drum riser is no help to solidify the kick sound Tim is great at. Amongst other things.

Yeah Steve hit it on the head.

My worst nightmare was doing sound for a church that bought an old catholic building. If you are familiar these are the structures built to project voices without electronic amplification.

Ex. Stand on one side of the dome and whisper, the guy on the other side can hear what you are saying clearly as if you were whispering in his ear.

They decided to build a hollow plywood 2x4 stage at the platform end of this and stack the band on top. What a hellish nightmare. The Drummer was at the top, so all you got was bounce around....

Well That pastor was too frugal (cheap, however you wanna look at it.) to spend anymore money besides the acoustical materials they placed at the back of the room.

That is where the old calm the band down thing really took major shape. I was able to make the room sound decent at about 96db at mix position. Of course eveness of frequencies was a fantasy, but I tuned the place so it was realtively somooth. At certain points (because he did'nt want to hang the speakers....All Ground Support) 125 - 250 would dip in and out about 6-9db. It worked and was passible by my standards.

How I wish we could have 705'd that dome ceiling..... LOL

Bryan Giles

zikaj · Post by **zikaj** » Sat Jul 19, 2003 4:06 am

Thanks to you guys.
Greatly appreciate it.

I had a pretty good grasp of what might need done, but hearing someone else say it really helps me make those decisions.

Here is are some answers to questions/comments y'all had:

BRYAN: YES- there is a monitor console. And when I looked at it yesterday, everyone was WAAAAYYY up.

STEVE:
Thank you for your extensive reply. I read about 2hours last night focusing on the choir getting some help. (I talked to the choir director yesterday and she listed her needs).
?Add some wood racing over the choir riser?

I've been thinking about how to get that guitar amp next to his head.

The MoPad type thing is on my map too. ...Or maybe suspend the amps from the ceiling on 30 foot long bungee cords?

I've got 6 sheets of 2" 703 and some 705 coming in today. We'll lean it on the back wall for now. I'm not going to commit to mounting it on the wall. I think that is too hasty and impulsive.

I'll crawl under the stage today and have a peak. As sell as check out those risers and how to use them effectively.

One last question- Can panel resonator bass traps be put inside those risers?
The stage is seemingly constantly being re-arranged and is used for multipurposes. Maybe make the acoustic treatments moveable on the rear wall (permanent on the sides) via Z-Clips. That would make it easy to adjust the acoustics for an area (like if the choir moves from center to the left side).

Thanks.

Jeff

giles117 · Post by **giles117** » Sat Jul 19, 2003 4:27 am

Not to beat the turn the volume down thing in the head...

But for years I traveled with The Spinners doing FOH and Monitors (I tuned and set them. The company Tech would babysit)

We did every kind of room imaginable. And a LOT of Corporate work. That was the beginning of my "Turn it down training" I had a very professional band which was a major help. One of the last gigs I did with them before retiring this year was Feb 14th in Charlotte.

It was your typical Cinderblock/very high ceiling Banquet room. Just like your Gymnasium.

With this pro Band we were able to keep stage volume at a very respectable level. I was guess about 93 or 94db. This was from years of training them to what they REALLY need in monitors, etc..... I took all that same theory and practical experience into the various churchs I've worked at. I have only had one church be resistant to change, but all the others I've consulted at that listend and took the training I gave are very pleased with what they have now.

Remember Monitors are just for what they need reinforcing.. Mainly themselves. They do not need the WHOLE band in the monitors.... Does a keybd player next to a gtr plyer need gtr in his mix?? NO!!!!!! So train them. Listen to their mixes during rehearsals and see what adjustments can be made. Even after you PAd the place down, they still need this training. An engineers 2nd job after giving them what they want is telling them what they need. Very carefully. LOL

Bryan Giles

zikaj · Post by **zikaj** » Sat Jul 19, 2003 9:20 am

Here's a few nuggets that are the latest:
The drums are on that 24" riser. Two 4 x8 foot sections. A plexiglass shield around the front and sides.
A & C Weighted measurement of playing the drums moderately:
back of church- 68-70 dB
Front row- 70 dB
Choir spot, Lead singers, keys, bass player...all else: 80dB.

Add another 80 from the percussion and another 75 from the bass (A wt.)

You get the idea.

I haven't read completely through the 2 new posts above this one. I'll have to wait til I get home.
One thing- they are willing to spend and do it right this time. (It wasn't planned when it was built.)

Looking forward to printing this stuff and reading it.
Thanks again a ton! Sorry, Thanks 909.09 Kilograms!:lol:

Jeff

knightfly · Post by **knightfly** » Sat Jul 19, 2003 9:34 am

Yeah, any and everything you can do to lessen the amount of crap in the air will help; we used to DI everything we possibly could just to minimize the # of open mics - made a huge difference in volume-before-feedback.

On the "riser as panel trap" thing - that might be the best way to go on those - if you can rubber mount to partially decouple them from the floor, then mount 705 (thicker the better) within about 1/2" of the TOP (inside, of course) adding whatever framing is necessary to support the 705 on fairly wide cleats, caulked, etc, then the riser would become its own panel trap.

If there's room below the main stage floor, and it's not habitable space, you could suspend 705 a couple of feet below the floor, then use John's bass hangers below that to kill that space so it can't come back at you.

If the hangers would be in the way of maintenance down there, you could just hang them on hooks and rods or something, so they could be set aside during any maintenance.

Bryan, the place (EWF) was such a madhouse I didn't even try to talk to sound people - just stuck in earplugs, tried to ignore the kick-triggered grenades, and went with the vibe - GAWD, Maurice is a freakin' DYNAMO - whatever he's on, I want some. He reminded me a lot of "Tigger", in winnie the pooh. And Phillip couldn't sing any higher if he had a Theremin up his... Anyway, it was a great show, but I'll probably not bother with concerts in that venue again, just wait til they happen in a better space... Steve

knightfly · Post by **knightfly** » Sat Jul 19, 2003 9:49 am

Oh, Jeff, here's a link that might help you get more confused -

http://www.networks-now.net/litresswrao ... elines.htm

Maybe his chart can help you decide what else may be needed in your particular case... Steve

zikaj · Post by **zikaj** » Sat Jul 19, 2003 11:28 am

>>>then mount 705 (thicker the better) within about 1/2" of the TOP (inside, of course) adding whatever framing is necessary to support the 705 on fairly wide cleats, caulked, etc, then the riser would become its own panel trap.

Just clarifying- are you saying to use the TOP of the riser as the resonating surface? Or rather, wouldnt I want to use the Top as the "bottom", then 2 inches of space, then fiberglass, then 1" space, then 1/4" plywood. All caulked and sealed.

>>>>If there's room below the main stage floor, and it's not habitable space, you could suspend 705 a couple of feet below the floor, then use John's bass hangers below that to kill that space so it can't come back at you.

Well, I THINK its 'habitable'. They make the bad kids from Youth Group sleep under their and eat dust mites for days when they don't raise enough money......
but they wouldn't mind some bass hangers under there.

I know I keep coming with the new questions (but like I said, I don't know about live/stage acoustics). Is there any use for diffusive surfaces on the stage rear wall? Just wondering about that one.

knightfly · Post by **knightfly** » Sat Jul 19, 2003 3:21 pm

"are you saying to use the TOP of the riser as the resonating surface? Or rather, wouldnt I want to use the Top as the "bottom", then 2 inches of space, then fiberglass, then 1" space, then 1/4" plywood. All caulked and sealed. " -

Crap, since you put it that way, it just dawned on me that the choir will be STANDING on the resonator my way - YOUR way, the resonator will be almost touching the BIG resonator (the floor) and I'd think that would be even worse... Might be better to leave the riser open on the bottom and put about 3" of spray foam on the underside of the TOP to cut down the resonance... I'm reaching here, not having ever done this experiment.

Sure wish I wasn't so dumb, mighta been able to help more here - Looks like, in the absence of serious experience in this area, you should start with the cheap quick things that seem like they might work...
-
As far as diffusion on the rear wall, it should work pretty much the same as other areas - if there's less than about 25 foot round trip from any of the sound sources (amps, etc) to the wall and back, then absorption should be used. In fact, I'd stick with absorption anyway, considering everyone wants to turn up - if they got a clearer sound, it wouldn't make them feel like they need more volume in order to hear.

Your earlier idea of leaning the 703 up against the rear wall is definitely a good starting place - then, if it doesn't help enough, try a few cans of spray foam under the riser tops to help kill the boom.

One way or another, you need to kill those resonant panels (floor, risers) - beyond that, if just 703 on the rear wall doesn't do it you might try leaning plywood up against the rear wall, horizontally at about 30-45 degrees, with the 703 in FRONT of the plywood - you get absorption and re-direction which will lower the echo on stage.

OK, I'm about done - anybody else??? Steve

zikaj · Post by **zikaj** » Sun Jul 20, 2003 5:07 pm

I built one giant panel today.

My wife showed up an hour in with Lunch! Which was nice. Until I got so excited I pushed my hand/fingers of my FRETTING HAND (left) onto an IMPAILING PLATE. Put about 20 holes in my hand/fingers. The plate is now happily securing two inches of 703 in a nice 6" deep frame.

So thats nice for it. As for me.....

OUCH.

I only got one panel done.

Shoot me an email and I"ll zip one back with the .pdf of the illustration I'm working with for the plans. Also has ALL of the monitors and amps for you viewing pleasure.
zika@bww.com

(if you're interested).

Thanks. Gotta sleep.
JZ

knightfly · Post by **knightfly** » Sun Jul 20, 2003 6:51 pm

Done, Jeff - you should have my email by now... Steve

zikaj · Post by **zikaj** » Mon Jul 28, 2003 12:46 pm

6 panels are done.

HUGE monstrosities. framed in 2x6 lumber (1/3 the price of 1x6 lumber = I can now ask them to buy a POD for the guitar!

)

They looked SO BIG, until they went up on a 32' high wall, 50 ' wide. I'm doing more with 2x4 sections and am going to probably do 1 or 2 more 4x8 panels.

They want to do bass traps in the rear of the house in the 2 main corners.

I also want to put them up above the stage areas in the rear corners, behind curtains. The wall doesn't start until 8' up from the floor, so that leaves...hmmm.....24 feet or so on each side.

Thoughts? Type?

The drum riser is DEAD with much plywood and fillers. Kick is MUCH better and it isn't so boomy.

The stage is one layer of 3/4" ply on steel 2x10s. Still think the baffling is a good idea under the stage? (hanging panels to kill resonances?)

And last- panel bass traps along those walls I mentioned earlier?

Oh, while I'm asking- good idea to reface the choir riser with wood, atleast for their sake? I don't know if the house hears them directly or not, but they can't hear a thing. As well, does the wall behind them effect them? ie- should I not have absorption panels behind them?

Thanks.

Jeff